Criteria-based rehabilitation exemplified by reconstruction of the anterior cruciate ligament

Returning to sporting activities or competitive sports is of great importance for most athletes after anterior cruciate ligament (ACL) reconstruction. The decision of the treating team to clear the athlete for unrestricted activities is currently still based on time-related and also individual musculoskeletal functional tests, which assess the function based on the limb symmetry index (LSI). However, the quality of the healthy contralateral side is usually unknown but is considered as the target value. By using simple musculoskeletal functional analysis it is difficult to assess the risk of injuries. In addition to biological and psychological parameters, biomechanical functional tests should also be carried out at defined return to phase points during the rehabilitation in order to be able to objectively assess the functional status. This enables the athlete to adequately increase the load with the lowest possible risk of injury. Using complex 3D motion analysis the quality of movement, exact joint angles and loading of joints as well as muscle activity can be objectively, reliably and reproducibly determined. However, these procedures are time-consuming and cost-intensive and also necessitate biomechanical and medical knowledge to assess the analytical data in terms of clinical relevance.